1. Field of Invention
The present invention relates to a luminescent assembly, and more particularly to a luminescent assembly with an increased brightness.
2. Description of the Related Art
A conventional luminescent apparatus such as a fluorescent light, light-emitting diode or the like has a luminescent intensity and a brightness that is determined by the luminescent intensity. Take the fluorescent light for example, this luminescent apparatus comprises a tube, a fluorescent coating, two electrodes and a noble gas and mercury vapor. The tube is vacuumed and has an inner surface, inner space, outer surface and two ends. The fluorescent agent is applied to or coats on the whole inner surface of the tube to form a fluorescent coating and has a thickness. The fluorescent coating has an outer surface and an inner surface. The inner surface is exposed to the inner space. The outer surface is in contact with the inner surface of the fluorescent tube. One electrode is mounted in the inner space at or near one end of the tube. The other electrode is mounted in the inner space at or near the opposite end of the tube. The noble gas and mercury vapor fill the inner space of the vacuumed tube. When electricity is applied to the electrodes, the negative electrode emits electrons that excite the noble gas and causes the mercury vapor to emit ultraviolet photons, which causes the fluorescent coating to emit visible light. The visible light passes through the fluorescent coating and the tube and is visible.
However, such fluorescent coating has the following shortcomings.
1. When the ultraviolet photons directly irradiate the fluorescent coating, the ultraviolet photons will excite the fluorescent coating that emits visible light. However, fewer ultraviolet photons penetrate the fluorescent coating to excite the outer surface of the fluorescent coating. Consequently, visible light created at the outer surface of the fluorescent coating will be weaker than that created at the inner surface.
2. The fluorescent coating is not a good translucent material and will decrease the percentage of visible light that passes through the fluorescent coating and cause the luminescent intensity of the visible light to be weak when it passes through the fluorescent coating to the outer surface.
The two characteristics result in reduced brightness and wasted electrical energy.
To solve the foregoing problems, the fluorescent coating may cover about only half of the inner side of the fluorescent tube, and other about half of the fluorescent tube is transparent. The ultraviolet photons irradiate the fluorescent coating on half of the inner side of the fluorescent tube, which emits visible light through the uncoated and transparent half of the fluorescent tube. However, ultraviolet photons will pass directly through the transparent half of the fluorescent tube and may damage the eyes and the skin of people exposed to the ultraviolet photons if the tube does not block the ultraviolet photons. Moreover, the ultraviolet photons that pass through the transparent half of the fluorescent tube do not irradiate the fluorescent coating, which significantly reduces the efficiency of the luminescent apparatus and waste electrical energy.
To overcome the shortcomings, the present invention provides a luminescent assembly with increased brightness to mitigate or obviate the aforementioned shortcomings.